connect-four/src/de/itsblue/ConnectFour/PlateContainer.java

/*
    Connect four - written in java
    Copyright (C) 2020 Oliver Schappacher and Dorian Zedler

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package de.itsblue.ConnectFour;

import javax.swing.JPanel;
import java.awt.*;

public class PlateContainer extends JPanel {

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    /**
     * holds the current contained plate object
     */
    private Plate containedPlate = null;

    /**
     * Constructor
     */
    PlateContainer() {
    }

    /**
     * Function to insert a plate into the container
     * 
     * @param plate the plate object to insert
     * @return true if inserted, false if container is alread occupied
     */
    public boolean insertPlate(Plate plate) {
        if (this.containsPlate())
            return false;

        System.out.println("adding plate " + plate);

        this.containedPlate = plate;

        return true;
    }

    /**
     * Function to get the contained plate
     * 
     * @return null or the contained plate
     */
    public Plate getContainedPlate() {
        return this.containedPlate;
    }

    /**
     * Function to check if the container is occupied
     * 
     * @return <code>true</code> if occupied
     *         <code>false</code> if not
     */
    public boolean containsPlate() {
        if (this.containedPlate != null)
            return true;
        else
            return false;
    }

    /**
     * Function to clear the container
     * 
     * @return if it was occupied: contained plate, else: <code>null</code>
     */
    public Plate removePlate() {
        if (!this.containsPlate())
            return null;
            
        Plate ret = this.containedPlate;
        this.containedPlate = null;

        return ret;
    }

    /**
     * Override the paint function to draw the shape of the plate
     */
    @Override
    public void paint(Graphics g) {
        // draw background
        g.setColor(Color.lightGray);
        g.fillRect(0, 0, this.getWidth(), this.getHeight());

        // set color according to contained plate
        if (this.containsPlate())
            g.setColor(this.containedPlate.getColor());
        else
            g.setColor(Color.white);

        // draw plate
        g.fillOval((int) (this.getWidth() * 0.1), (int) (this.getHeight() * 0.1), (int) (this.getWidth() * 0.8),
                (int) (this.getHeight() * 0.8));
    }
}